package com.changgou.web.gateway.filter;

import com.changgou.web.gateway.service.AuthService;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class AuthFilter implements GlobalFilter, Ordered {

    //定义没登录情况下401页面跳转到登录页面的路径地址
    private static final String LOGIN_URL="http://localhost:8001/api/oauth/toLogin";

    @Autowired
    private AuthService authService;


    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        //获取请求和响应对象
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();

        //1.判断当前请求是否是登录请求,如果是,直接放行
        String path = request.getURI().getPath();
        if("/api/oauth/login".equals(path) || !UrlFilter.hasAuthorize(path)){
            //直接放行
            return chain.filter(exchange);
        }
        //2.从cookie中获取jti的值,如果该值不存在,则拒绝访问
        String jti=authService.getJtiFromCookie(request);
        if(StringUtils.isEmpty(jti)){
            //拒绝访问,申明当前没有权限
            /*response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();*/

            //跳转登录页面(携带参数登录成功后要跳回之前访问的页面全路径)
            return this.toLoginPage(LOGIN_URL+"?FROM="+request.getURI().getPath(),exchange);

        }

        //3.从redis中获取jwt令牌,如果该值不存在,则拒绝访问
        String jwt=authService.getJwtFromRedis(jti);
        if(StringUtils.isEmpty(jwt)){
            //拒绝访问,申明当前没有权限
            /*response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();*/

            //跳转登录页面
            return this.toLoginPage(LOGIN_URL,exchange);
        }

        //4.对当前请求对象进行增强,让它携带令牌信息(请求头信息进行增强)
        request.mutate().header("Authorization","Bearer "+jwt);

        //5.放行
        return chain.filter(exchange);
    }

    /**
     * 跳转登录页面
     * @param loginUrl
     * @param exchange
     * @return
     */
    private Mono<Void> toLoginPage(String loginUrl, ServerWebExchange exchange) {
        ServerHttpResponse response = exchange.getResponse();
        //SEE_OTHER状态码是302,来完成跳转
        response.setStatusCode(HttpStatus.SEE_OTHER);
        //Location不能更改,设置跳转头信息
        response.getHeaders().set("Location",loginUrl);
        return response.setComplete();
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
